TurboGrafx-16 Contrast Issue

[The Eva Monkey]

I picked up a TurboGrafx-16 off of eBay. I sought out one with a TurboBooster specifically because I am particular about image quality. For some reason, the system is outputting an image that is particularly dark, or high contrast. I've noticed that fiddling with the video connection can result in a temporary change to what I perceive to be the correct brightness and color saturation.

I've tried different cables, I've tried it with and without the TurboBooster attached, I've tried using different inputs on the TV. As far as I'm aware, it's a problem with the system itself. Any help or suggestions would be appreciated.

Video:


Image Comparison:


After making the video, and taking the screenshots, I tried the system out with an older Trinitron SD CRT, and the picture comes through just as expected. I've never had any issues with hooking my systems up to my Samsung HD CRT, but I'm wondering if there's an issue with using a TG16 with an HD CRT.

[Jontendo]

I'm guessing the resistor value NEC put in line with the video out is tailored to what a CRT display expects (75 ohms). The odd part is that LCDs usually display the image brighter.

Is it safe to assume other composite sources display no contrast issues on your LCD?

[The Eva Monkey]

Is it safe to assume other composite sources display no contrast issues on your LCD?

It's not an LCD, it's a Samsung Slimtube CRT. Like I said, I haven't had an issue like this with other systems. I have 12 other systems hooked up, including my Genesis and NES on composite, and neither of them have this issue. I hooked it up to my standard def trinitron crt and the image looked great, which makes me wonder if it's an issue with scaling or something of that nature. I actually wish I had an LCD display handy to test, but my only LCD is a VGA/DVI/HDMI monitor.

[Jontendo]

Scaling is only an issue with LCDs as they're stuck with a fixed-pixel (native) resolution. CRTs don't have to worry about scaling up or down to fit such a "mold" (so to speak).

Your best bet may be a compromised setting, bumping the brightness/contrast to a level that looks acceptable between all the consoles. :/

I think that particular TV just might not be 100% cool with the output level of the TG16, especially given that you said contrast looked good on the other monitor.

[The Eva Monkey]

Scaling is only an issue with LCDs as they're stuck with a fixed-pixel (native) resolution. CRTs don't have to worry about scaling up or down to fit such a "mold" (so to speak).

This is drifting somewhat, but I was researching recently along this topic in regards to lightguns. My understanding is that the reason lightguns don't work on HD CRTs is for the same reason as LCDs, input lag from video scaling.

I think that particular TV just might not be 100% cool with the output level of the TG16, especially given that you said contrast looked good on the other monitor.

As in the video signal doesn't have enough power behind it? If that's the case, I'll have to experiment with running the TG16 through a VCR or distribution amplifier.

[Jontendo]

This is drifting somewhat, but I was researching recently along this topic in regards to lightguns. My understanding is that the reason lightguns don't work on HD CRTs is for the same reason as LCDs, input lag from video scaling.

If it's doing any image processing between the source & display, there will be some lag which could make a lightgun unusable. With a CRT, there should be no lag due to scaling. De-interlacing, ghost reduction and other processing are very possible culprits for lag on a CRT set though.

As in the video signal doesn't have enough power behind it? If that's the case, I'll have to experiment with running the TG16 through a VCR or distribution amplifier.

It'd be worth a try if you already have that stuff.

[The Eva Monkey]

It'd be worth a try if you already have that stuff.

So after a variety of experiments, I've arrived at three different solutions.

1) Using my Trinitron SD CRT instead of my Samsung HD CRT.
2) Running the TG16 through a VCR into my Samsung HD CRT.

The weird one:

3) Running the TG16 into my Samung HD CRT via one input, and the VCR into the other input. Turn both of them on. Switch first to the VCR, so you get the blue screen, then switch to the TG16. The video will now be correct. WTF I don't even? I tried a similar variant of running an NES in place of the VCR, but did not get the same result.

WHUT? Anyone else use a TG16 with an HD CRT monitor?

[Hobie-wan]

I don't even have a CRT with coaxial input anymore, otherwise I'd test for grins.

[Majors]

It'd be worth a try if you already
3) Running the TG16 into my Samung HD CRT via one input, and the VCR into the other input. Turn both of them on. Switch first to the VCR, so you get the blue screen, then switch to the TG16. The video will now be correct. WTF I don't even? I tried a similar variant of running an NES in place of the VCR, but did not get the same result.

So when you have your VCR hooked up and powered on, the TG-16 (on another input) looks fine?

I have a small 13" CRT that has a/v in and out. I discovered that when something in connected to the output, it will drop my brightness. I can compensate with the manual adjustments. Also, I have a couple of Sony CRTs that offer a video out (monitor)...and I seem to recall when something is connected it will effect the main display (I recon' the signal is getting split).

You tried hooking the TG into all the composite inputs on the TV? No difference? You remove the AV Booster and run RF only?

Since it runs fine on your Sony, it must be NEC fighting with the Samsung (Japanese don't like the Koreans!)

Maybe a CD-ROM attachment will fix it

[The Eva Monkey]

So when you have your VCR hooked up and powered on, the TG-16 (on another input) looks fine?

Close, both hooked up and powered up on different inputs. But you have to switch to the input with the VCR so you get the blue screen, and then switch to the TG16, and the image appears to be corrected.

You tried hooking the TG into all the composite inputs on the TV? No difference? You remove the AV Booster and run RF only?

The issue exists on both, I just noticed that if (while on RF) I fiddle with the connector, I can trigger it to correct the image. All my experimentation and troubleshooting has involved running it on composite. RF can suck it.

My solution is probably just going to be using it with my second setup whenever I get around to putting it together. The Trinitron is for the second setup which is mostly going to be for DDR/Motion games and Lightgun games.